Many of the circuits used in telephone central offices have fuse devices located in the circuits to protect the equipment from current surges. Typical of the fuses used in these arrangements is the 70 type, or tubular shaped, fuse (manufactured by Western Electric Company, Incorporated of New York, N.Y.), which is inserted into a fuse holder for connection to the electrical circuit which it protects. The fuse holder has a tubular shaped opening designed to accept the fuse and has two leads embedded in the walls of the opening and one lead coiled at the bottom of the opening.
Frequently, circuits using tubular type fuses must be tested to assure proper electrical continuity. Since the fuse holder for tubular type fuses has two leads embedded in the wall of the tubular opening, making electrical contact with these leads has proved to be physically difficult. In one previous arrangement, a dummy tubular fuse is inserted into each fuse holder opening and, because of the location of the embedded leads, is turned by the test operator until electrical contact is made with each embedded lead for test purposes. However, this arrangement is time consuming and, because of the numerous inserting, turning and pulling out operations of the dummy fuse by the test set operator during the work day, has resulted in operator fatigue and in poor test results.